Between Aardenburg and Wilhelm, there's plenty of information out there regarding the lightfastness of various ink-paper combinations (in general HP Vivera > Canon Lucia > Epson Ultrachrome) - but, of course, that's only part of the equation. Degradation by ozone and other atmospheric pollutants is just as much a factor in the deterioration of prints (more so in dark storage, or in dimly-lit homes and other display environments), and microporous inkjet coatings are much more susceptible to this than uncoated papers and gelatin prints, due to their greater surface area. Spray coatings and laminates mitigate this somewhat (this, and the physical protection from scuffing and moisture, may be more important to inkjet prints than the increased UV protection provided by these coatings), especially if the spray is applied to the reverse and edges of the print as well as the front, but how effective are they, really, at sealing the billions of pores in a typical inkjet print? And, of course, it's no good having a permanent print if the substrate deteriorates from atmospheric contaminants, from remnants of the print method, or from the ink or pigment itself - platinum prints may last forever, but a lot of century-old platinum prints are now extremely brittle and fragile, if not stained and falling apart, due to the catalytic conversion of gaseous sulfur dioxide and water in the atmosphere into sulfuric acid, which attacks the paper, despite leaving the platinum itself untarnished.

So, in a similar vein to Aardenburg and Wilhelm for lightfastness, do we have any good sources of information at the moment regarding the chemical and humidity resistance of various print method/ink/substrate/sealant combinations? As in, actual tests on specific combinations, not just general and theoretical documents?

So, in a similar vein to Aardenburg and Wilhelm for lightfastness, do we have any good sources of information at the moment regarding the chemical and humidity resistance of various print method/ink/substrate/sealant combinations? As in, actual tests on specific combinations, not just general and theoretical documents?

Henry does do testing for UV, humidity and ozone resistance but doesn't quantify the results, just gives general terms...the Image Permanence Institute (IPI) does testing for environmental conditions. Sadly, the IPI does contract testing and does not publish much publicly. There are some free papers and some paid for books...and they have a pretty cool online print comparison tool called the Graphics Atlas...

Henry does do testing for UV, humidity and ozone resistance but doesn't quantify the results, just gives general terms...the Image Permanence Institute (IPI) does testing for environmental conditions. Sadly, the IPI does contract testing and does not publish much publicly. There are some free papers and some paid for books...and they have a pretty cool online print comparison tool called the Graphics Atlas...

Thanks.

Or course, there's also the question of degradation of the inkjet receptive coating itself, independent of degradation of the ink - silica and ceramics are chemically unreactive, but polymer layers may be subject to UV or chemical attack, as may any binders holding silica and ceramic particles in place. Also, they may be brittle, like baryta layers.

One of the reasons I'm asking is that Jon Cone, along with one or two other printmakers, has a process by which they use a Roland solvent printer to print aqueous pigment inks onto thick, uncoated Japanese or watercolour papers, heating the ink and paper for near-instant evaporation to increase the ink load and minimise bleeding (which, after all, is the purpose of the receptive coating in the first place). This would have the effect of drastically improving resistance to ozone and other pollutants compared to a microporous coating, due to the much smaller surface area exposed to the atmosphere; however, I'm not certain of the UV resistance of Cone's custom-made colour pigment inks (the longevity of the carbon inks for black-and-white printing is undisputed). So, the question I am trying to answer is this: when framed under museum glass and displayed in a typical room (moderate illumination, in a city with its usual atmospheric pollutants, with electrical devices adding to the atmospheric ozone), which will last longer without fading - a colour print using Cone pigment inks on uncoated paper, and sprayed with a protective spray, or a colour print on Photo Rag Pearl (or a similar paper) using highly lightfast HP Vivera pigment inks and sprayed with a protective spray?

Could a scholarly answer to your questions about gas fade resistance be given? You bet. The I* metric and test targets used by Aardenburg Imaging & Archives for light fade studies would do a fantastic job at evaluating gas fade resistance. Of course, it would require about $100K in ozone generating equipment and monitoring instrumentation, and labor for each test would be about $1K per sample. Who would pay for this work, the manufacturers or the end user? Likely neither!

I base my conclusion on the fact that the light fade studies I publish at no charge to the printmaking community fortunately took significantly less equipment investment than gas fade studies yet require about the same level of labor per sample as substantive gas fade tests. The light fade tests have been carried at a loss on my company books since I began doing them over six years ago. I rationalize the effort as a loss leader to other things I do, but I just can't take on any more of this "free information" initiative for the printmaking community, and I don't see how to properly fund any new work without jeopardizing the true independence of the research. Let me know if you have any brilliant funding ideas, but bear in mind that manufacturers will only sponsor tests when they can control the message, and that means you will hear only what manufacturers want you to hear.

Could a scholarly answer to your questions about gas fade resistance be given? You bet. The I* metric and test targets used by Aardenburg Imaging & Archives for light fade studies would do a fantastic job at evaluating gas fade resistance. Of course, it would require about $100K in ozone generating equipment and monitoring instrumentation, and labor for each test would be about $1K per sample. Who would pay for this work, the manufacturers or the end user? Likely neither!

I base my conclusion on the fact that the light fade studies I publish at no charge to the printmaking community fortunately took significantly less equipment investment than gas fade studies yet require about the same level of labor per sample as substantive gas fade tests. The light fade tests have been carried at a loss on my company books since I began doing them over six years ago. I rationalize the effort as a loss leader to other things I do, but I just can't take on any more of this "free information" initiative for the printmaking community, and I don't see how to properly fund any new work. Let me know if you have any brilliant funding ideas, but bear in mind that manufacturers will only sponsor tests when they can control the message, and that means you will hear only what manufacturers want you to hear.

I guess there just isn't enough awareness in the photo and fine art community of longevity and permanence issues with inkjet prints, as well as prints produced using other methods - and, out of those who are aware, too many who think that UV degradation of pigment is the only issue. Most likely through ignorance, too many people are just too happy to take Epson's claim of 100-year UV resistance for Ultrachrome inks at face value, without really knowing what it means, and without even considering the longevity of the paper, plastic or canvas on which the print is made (same with the claims of permanence for platinum prints).

If there were sufficient awareness of these issues, I am sure there would be much more funding available for independent tests, as paper, ink and laminate manufacturers would then have to compete on these ratings, not just claimed values of UV resistance for inks.

Also, do we even know how durable inkjet receptive coatings are? It may well be that printing on sized, but uncoated paper is a much better option for archival prints than printing on any sort of coated medium...

Also, do we even know how durable inkjet receptive coatings are? It may well be that printing on sized, but uncoated paper is a much better option for archival prints than printing on any sort of coated medium...

This area of inquiry was actually my area of specialization when I was working for the Smithsonian Institution some years ago. My colleagues and I did extensive research on mechanical/physical properties of photographic gelatin and it's role in "coated" photographic paper durability over time. The research methods we used would be very amenable to modern inkjet media. In other words, a very accessible topic for chemical and physical properties research of coated papers, but again, who pays for the work? I'm no longer on the American tax payer's bank roll. Those cultural heritage research budgets shrunk away as other government initiatives took more precedent. This is one reason so many of these questions go unanswered today, and why the internet serves up of lots of speculation and guesses without any concrete facts. After all, you've got your digital image file, right? Who needs a permanent print?

I suppose if my boss said, "see what you can find out about all this stuff", I'd arrange an appointment with the conservators at the National Galleries in my country. I know they have a great reputation and hopefully would refer me on to where all this information is used by people in their daily work.

I've seen some of their restoration and conservation work and I'm sure they have similar issues to us. Generally, in my experience, professionals are only too happy to pass on their expertise.

I suppose if my boss said, "see what you can find out about all this stuff", I'd arrange an appointment with the conservators at the National Galleries in my country. I know they have a great reputation and hopefully would refer me on to where all this information is used by people in their daily work.

I've seen some of their restoration and conservation work and I'm sure they have similar issues to us. Generally, in my experience, professionals are only too happy to pass on their expertise.

The general approach is conservation of what they did collect over time, not rules formulated or checks done for any art purchase or gift before intake. An artist with enough fame can drop a print on newspaper and it will be in the collection. Then there is enough money available to keep a team busy in restoration. Conservators will visit conferences on that subject all the time. The price of the collection is of more importance than the quality of the media purchased. That construction does not lead to preventative measures on the intake side. True, I have seen a project to test Diasec basics but I do not see it done. Recently a project is started that takes 600.000 Euro and its description made me think it can only be to preserve work by one contemporary artist that is in many Dutch collections. We have always been skeptical about the media properties of that work. It sure has art quality.

So, the question I am trying to answer is this: when framed under museum glass and displayed in a typical room (moderate illumination, in a city with its usual atmospheric pollutants, with electrical devices adding to the atmospheric ozone), which will last longer without fading - a colour print using Cone pigment inks on uncoated paper, and sprayed with a protective spray, or a colour print on Photo Rag Pearl (or a similar paper) using highly lightfast HP Vivera pigment inks and sprayed with a protective spray?

Ozone is so reactive that it will never go under the glass under normal concentration. It will be destroyed on the glass. You really need very high concentration of ozone if you want some of it to find the way to the framed print, so high that you can smell it, even than it will be neglectable amount of ozone that can reach the print, especially if it is sealed on the back.My postgraduated study was about troposferic ozone, so I know what I am talking.

Ozone is so reactive that it will never go under the glass under normal concentration. It will be destroyed on the glass. You really need very high concentration of ozone if you want some of it to find the way to the framed print, so high that you can smell it, even than it will be neglectable amount of ozone that can reach the print, especially if it is sealed on the back.My postgraduated study was about troposferic ozone, so I know what I am talking.

Absolutely and the larger question is what the level of indoor ozone concentrations are likely to be (I suspect quite small). This might only be an issue if you were displaying a print outside in an area where there is a lot of ozone generation by automobiles and industrial sources.

Absolutely and the larger question is what the level of indoor ozone concentrations are likely to be (I suspect quite small). This might only be an issue if you were displaying a print outside in an area where there is a lot of ozone generation by automobiles and industrial sources.

Even with air conditioners, computers, TVs and any number of other electronic devices producing ozone? Also, combustion byproducts, e.g. candles and kitchens in restaurants, incense in temples and Orthodox churches, the atmosphere in cities, often include some sulfur dioxide, which eventually forms sulfuric acid, which is another significant source of oxidative attack on pigments and their substrates.

The other major issue is substrate stability - after all, a print only lasts as long as whatever it's printed on. Uncoated paper and canvas have hundreds of years of proven survivability in Europe, sometimes in suboptimal storage conditions. Paper also has more than a thousand years of proven survivability in China and Japan. Gelatin and gum arabic are also proving very stable, provided humidity is controlled. In contrast, the polyethylene and polyester coatings on RC papers have shown significant degradation after just a few decades. Inkjet coatings may be made from silica or various clays (many are also plastic), but the binder that holds them together is usually also some kind of oil-derived polymer. It'd be very useful to know how long these last - or, in forty years time, we might just find ourselves with layers of expensive, pigmented dust, falling off the front of perfectly-intact, high-quality paper backings.

Have there been any serious efforts made into getting more pigment and less spreading onto proven, uncoated papers, or is it all about new, special unproven coatings these days? After all, the final pigment load and dot gain is all about pigment concentration in ink and drying time (whether by wicking away the solvent or by evaporation). Thicker ink and higher temperatures should help in each case. Shouldn't be too hard - after all, we now have inkjet printers which can print 3D objects using molten plastic, and experimental printers which an even print functioning livers!

Have there been any serious efforts made into getting more pigment and less spreading onto proven, uncoated papers, or is it all about new, special unproven coatings these days?

When framed under a suitable glazing like acrylic or glass, informed collectors can protect a print to a large extent from gas pollutants. We can control light levels, temperature and humidity as well. However, many prints are stored "loose" or in albums that don't prevent airborne contaminants from discoloring the edges, and that edge discoloration sometimes reaches beyond margins and into image content. I've collected inkjet media sample books for several years, and in my rural location (Berkshire mountains of Western Massachusetts) well away from heavy industrial pollutants, I'm already observing the vast majority of microporous papers in these sample books exhibiting measurable discoloration on borders up to about 1 inch into the paper. Sometimes subtle, sometimes disturbingly obvious for samples that are now only a few years old. This issue definitely concerns me and suggests that the huge porous surface area associated with modern microporous coated media is indeed susceptible at a very rapid rate of uptake to airborne pollutants, ozone being a notable one, but S02, NO3, etc., also of concern. Bottom line, we need more research on sensitivity of modern microporous inkjet media to airborne pollutants, and we need to better understand the role of top coatings in protecting these highly "sensitized" microporous image layers from discoloration over time. Add to this issue the problems I'm seeing with light induced, post exposure dark storage staining of many modern RC papers, and we've got some critically important research still ahead. Yet this important work faces a general industry and consumer perception that pigmented inks have solved all the print stability problems. I wish pigmented inks had indeed fixed all the issues, but the evidence I have in my own laboratory samples suggests otherwise.

Again, I ask who will pay to see this research conducted, so that we can coax manufacturers into solving these issues they either aren't aware of yet, or choose to ignore because their customers will not likely be able to source the problems back to them? IMHO, The museum world isn't going to take this research challenge on any time soon. The manufacturers aren't going to take this on, either. That leaves us, the end users, to spearhead any efforts to better understand and improve the situation. I don't wish to sound cynical, but it's just not looking like a promising area of research in terms of finding the funding necessary to address these issues in any meaningful way.

When framed under a suitable glazing like acrylic or glass, informed collectors can protect a print to a large extent from gas pollutants. We can control light levels, temperature and humidity as well. However, many prints are stored "loose" or in albums that don't prevent airborne contaminants from discoloring the edges, and that edge discoloration sometimes reaches beyond margins and into image content. I've collected inkjet media sample books for several years, and in my rural location (Berkshire mountains of Western Massachusetts) well away from heavy industrial pollutants, I'm already observing the vast majority of microporous papers in these sample books exhibiting measurable discoloration on borders up to about 1 inch into the paper. Sometimes subtle, sometimes disturbingly obvious for samples that are now only a few years old. This issue definitely concerns me and suggests that the huge porous surface area associated with modern microporous coated media is indeed susceptible at a very rapid rate of uptake to airborne pollutants, ozone being a notable one, but S02, NO3, etc., also of concern. Bottom line, we need more research on sensitivity of modern microporous inkjet media to airborne pollutants, and we need to better understand the role of top coatings in protecting these highly "sensitized" microporous image layers from discoloration over time. Add to this issue the problems I'm seeing with light induced, post exposure dark storage staining of many modern RC papers, and we've got some critically important research still ahead. Yet this important work faces a general industry and consumer perception that pigmented inks have solved all the print stability problems. I wish pigmented inks had indeed fixed all the issues, but the evidence I have in my own laboratory samples suggests otherwise.

Why can't the edges of prints, as well as the front and back, be sealed with acrylic sprays currently used to protect prints? Also, is there any reason pigment couldn't be mixed in with the water-based acrylic and applied via inkjet printer, the print then being composed of pigmented acrylic, rather than pigment sealed behind a layer of acrylic?

In any case, pigments may not be the answer to image permanence anyway. Nanoparticle 'pigments', based on quantum properties related to particle size rather than chemical composition, can replicate the colour of every pigment out there and more, including 'colours' in the infrared and ultraviolet wavelengths. And, unlike pigments, you can make them out of chemically-inert gold, carbon or silica, which aren't vulnerable to UV or chemical attack at all. Some examples here: http://nanocomposix.com/kb/general/color-engineering

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Again, I ask who will pay to see this research conducted, so that we can coax manufacturers into solving these issues they either aren't aware of yet, or choose to ignore because their customers will not likely be able to source the problems back to them? IMHO, The museum world isn't going to take this research challenge on any time soon. The manufacturers aren't going to take this on, either. That leaves us, the end users, to spearhead any efforts to better understand and improve the situation. I don't wish to sound cynical, but it's just not looking like a promising area of research in terms of finding the funding necessary to address these issues in any meaningful way.

It's stupid for museums and archives not to fund this sort of research - finding out the problems now, and working out solutions, will be ten times cheaper than fixing the same problems in the future. That is, if they can even be fixed - inkjet prints aren't the most amenable to restoration (unlike a painting, you can't just fix it with more paint), and no amount of restoration work can restore a print that's turned to dust. Better that they find out now which substrates/materials are durable and which ones aren't, than they find out in fifty years' time that all the inkjet prints made on coated paper at the turn of the millennium are completely worthless, and that there's no software left that can read 16-bit TIFF and 8-bit JPEG files.

How much does this sort of research (accelerated ageing tests of substrates under UV and chemical attack) cost anyway? Are we talking thousands, tens of thousands, hundreds of thousands, or millions?

Even with air conditioners, computers, TVs and any number of other electronic devices producing ozone? Also, combustion byproducts, e.g. candles and kitchens in restaurants, incense in temples and Orthodox churches, the atmosphere in cities, often include some sulfur dioxide, which eventually forms sulfuric acid, which is another significant source of oxidative attack on pigments and their substrates.

It's been a lot of years since I took photochemistry as part of my undergraduate chemistry degree but I seem to recollect that it's the nitrogen dioxide and the high energy light source that is responsible for atmospheric ozone production. Sulfur dioxide is a key component in smog but doesn't impact ozone production and level inside of a house is still likely to be quite small. The biggest worry about prints in a home situation is direct exposure to sunlight or some other high intensity light.

Even with air conditioners, computers, TVs and any number of other electronic devices producing ozone? Also, combustion byproducts, e.g. candles and kitchens in restaurants, incense in temples and Orthodox churches, the atmosphere in cities, often include some sulfur dioxide, which eventually forms sulfuric acid, which is another significant source of oxidative attack on pigments and their substrates.

The other major issue is substrate stability - after all, a print only lasts as long as whatever it's printed on. Uncoated paper and canvas have hundreds of years of proven survivability in Europe, sometimes in suboptimal storage conditions. Paper also has more than a thousand years of proven survivability in China and Japan. Gelatin and gum arabic are also proving very stable, provided humidity is controlled. In contrast, the polyethylene and polyester coatings on RC papers have shown significant degradation after just a few decades. Inkjet coatings may be made from silica or various clays (many are also plastic), but the binder that holds them together is usually also some kind of oil-derived polymer. It'd be very useful to know how long these last - or, in forty years time, we might just find ourselves with layers of expensive, pigmented dust, falling off the front of perfectly-intact, high-quality paper backings.

Have there been any serious efforts made into getting more pigment and less spreading onto proven, uncoated papers, or is it all about new, special unproven coatings these days? After all, the final pigment load and dot gain is all about pigment concentration in ink and drying time (whether by wicking away the solvent or by evaporation). Thicker ink and higher temperatures should help in each case. Shouldn't be too hard - after all, we now have inkjet printers which can print 3D objects using molten plastic, and experimental printers which an even print functioning livers!

Yes even with electronic devices in house - can you smell ozone - probably no - even if you can framed under glass print is protected.

Other items that you list have no connection to the ozone which is discussed in this thread.

It's been a lot of years since I took photochemistry as part of my undergraduate chemistry degree but I seem to recollect that it's the nitrogen dioxide and the high energy light source that is responsible for atmospheric ozone production. Sulfur dioxide is a key component in smog but doesn't impact ozone production and level inside of a house is still likely to be quite small. The biggest worry about prints in a home situation is direct exposure to sunlight or some other high intensity light.

Exactly - there are oxydizing polutants which are generated mostly by nitrogen oxides and sun.

There are also reducing polutants which is mostly generated by burning coal with high sulfur content - smog is "smoke and fog" which is this type of polutant.

Yes even with electronic devices in house - can you smell ozone - probably no - even if you can framed under glass print is protected.

Other items that you list have no connection to the ozone which is discussed in this thread.

They don't produce ozone, but they produce other pollutants (e.g. SO2, which is oxidised and hydrated to form H2SO4) which are oxidative agents, attacking prints and substrates in a similar fashion to ozone.

They don't produce ozone, but they produce other pollutants (e.g. SO2, which is oxidised and hydrated to form H2SO4) which are oxidative agents, attacking prints and substrates in a similar fashion to ozone.

Again, I ask who will pay to see this research conducted, so that we can coax manufacturers into solving these issues they either aren't aware of yet, or choose to ignore because their customers will not likely be able to source the problems back to them? IMHO, The museum world isn't going to take this research challenge on any time soon. The manufacturers aren't going to take this on, either. That leaves us, the end users, to spearhead any efforts to better understand and improve the situation. I don't wish to sound cynical, but it's just not looking like a promising area of research in terms of finding the funding necessary to address these issues in any meaningful way.

This sort of small-scale research is unlikely to attract commercial funding and, being conducted by individuals rather than universities or large research institutions, is unlike to attract research grants either.

The best method may be Internet-based microfinancing from the photographic and art communities (who also make and sell inkjet prints of their paintings and drawings, or incorporate inkjet printing as the background of mixed-media works), many of whom have a vested interest in making their work last as long as possible.

Of course, asking for donations is never going to generate revenue. People generally want something tangible and immediate for their money.

Which brings me to a possible solution. Over on Photography on the Net, we have just finished the fourth edition of a 'yearbook' type photo book, showcasing the best work of members. Thousands of contributions were made and voted on, the best ones making it into the book.

Naturally, this was done in a strict not-for-profit manner, but there's no reason the same process couldn't be turned to generate revenue for research. If a copy costs $60 to print (plus extra for delivery, depending on where in the world you want it delivered), it wouldn't be unreasonable to charge $100 it, and you'd get a lot of buyers. Pretty much everyone with a photo in it would buy one copy (if not more) and, with high-quality work and presentation, as well as a good online sample available, you'd be able to sell even more. After all, a photo book is something you want as a tangible object, not just a pirated PDF file. On POTN, even many people who didn't have a photo in the final publication bought a copy. At $40 profit per copy, twenty-five copies would give you the $1000 for a test, and a sale of 400 copies would be easily achieved on just one forum. Multiply this via publicity (and entrance) on multiple forums (including art/painting forums), and you could pay for a lot of testing. Since they're getting something tangible and high-quality, quite possibly with their own work in it, and knowing that proceeds would go towards research in which they had a personal vested interest, proceeds from a group project like this would be much higher than that which could be generated by just soliciting donations, or membership fees for access to a data table and some PDFs. Also, major forums like this tend to attract top-tier photographers, many of whom have their work in galleries, or who turn a profit selling photos. A photo book like this would be able to attract sales to the general public (albeit at a relatively low volume), while providing extra publicity for the artists (after all, having a photo in a photo book isn't the same as having the same photo printed at 30x90" and hanging on your wall, so you wouldn't be cannibalising sales - it's more like a catalogue).